Feature Service Layer Not Appearing in AGOL

A Feature Service layer I created from Desktop and shared for AGOL is not appearing in the Map Viewer online. In the Item Details, the thumbnail shows the layer and symbology as a preview, but when I add to the map, it doesn't draw. It does appear in the table of contents on the left, and all the functions for editing it appear to be operating normally...just doesn't draw.

I had this once, which was related to errors in some geometries of the featureclass that I published. Run Repair Geometry—Help | ArcGIS Desktop on a copy of you data to see if there are any problems in the data and republish.